As part of the large-scale electrical power generation in the United States and Canada, massive burning of hydrocarbon fuels is required for power plants that are fired by coal, oil or natural gas. It is generally accepted that serious environmental problems arise during the production of electric power using any of these hydrocarbon fuels, albeit some less than others. Greenhouse gases are generated and released into the atmosphere, and many other contaminants are brought to the surface and must be dealt with using expensive and sometimes ineffective processes.
With each step in the processes of extracting, refining, transporting and ultimately burning any hydrocarbon for use in a distant power plant or car, considerable damage is done to the environment. Each of these process steps is also expensive.
If contained hydrocarbon reservoirs were burned in situ underground, and only heat energy was extracted to the surface, and the heat energy was applied to generate electrical power, which was transmitted to the continental electricity grids, and then to electric cars, electric heating and electric-focused industries we would have a far more efficient and cost-effective energy system. If we could get more hydrocarbons usably available from each of our hydrocarbon resources we would make our overall hydrocarbon resources last longer. In so doing, if we could also eliminate greenhouse gases and other contaminants resulting from the recovery and use of hydrocarbons, we would help considerably in solving three major current world problems, namely, the need for cheaper energy, the need for more abundant and dispersed energy, and the need for much greater reductions in greenhouse gases emissions and contaminants.
It is known in the art of power generation to burn fossil fuels in situ underground and extract the heat energy to the surface. Examples in the patent literature include Reynolds et al., U.S. Pat. No. 4,018,279; Cooper, U.S. Pat. No. 4,063,416; Birch, U.S. Pat. No. 4,557,328; and Uselton, US 2010/0251728. However, the prior systems do not avoid the problems of environmental contaminants being transported to the ground surface, or combustion gases being released into the atmosphere, even though the burning occurs underground.
Successful in situ combustion of hydrocarbon reservoirs has been conducted since at least the early 1960's (see SPE/DOE 24200 Case History dated 1992 on South Belridge, Calif., In Situ Combustion Oil Recovery by Mobil Oil, which carried on the process for over 22 years in a heavy oil reservoir). Large scale steam turbine power plants have been around for nearly 100 years. It would be desirable to link these two old technologies—in situ combustion heat (or other forms of subterranean heat) and steam turbine power plants (or other commercial heat uses). In order to change the location of where and how hydrocarbons are burned, the main technology that has been missing is the ability to efficiently transfer heat energy from underground up to the surface to a user.